Refactor program stage management

There can't bee a huge number of stages in a program so a fixed-size
array takes less space than a vector.  It also allows accessing ids of
specific stages if needed.

diff --git a/source/core/program.cpp b/source/core/program.cpp
index 038c031393ae33a5fcaeee27a1c00910f5da0c3c..d6bd5ee88d889c4efc02a0b9ee86a8051b8ec9a2 100644 (file)
--- a/source/core/program.cpp
+++ b/source/core/program.cpp
@@ -70,6 +70,7 @@ void Program::init()
        static Require _req(ARB_shader_objects);
 
        id = glCreateProgram();
+       fill(stage_ids, stage_ids+MAX_STAGES, 0);
        module = 0;
        transient = 0;
        linked = false;
@@ -77,14 +78,15 @@ void Program::init()
 
 Program::~Program()
 {
-       for(vector<unsigned>::iterator i=stage_ids.begin(); i!=stage_ids.end(); ++i)
-               glDeleteShader(*i);
+       for(unsigned i=0; i<MAX_STAGES; ++i)
+               if(stage_ids[i])
+                       glDeleteShader(stage_ids[i]);
        glDeleteProgram(id);
 }
 
 void Program::add_stages(const Module &mod, const map<string, int> &spec_values)
 {
-       if(!stage_ids.empty())
+       if(has_stages())
                throw invalid_operation("Program::add_stages");
 
        switch(mod.get_format())
@@ -95,18 +97,30 @@ void Program::add_stages(const Module &mod, const map<string, int> &spec_values)
        }
 }
 
-unsigned Program::add_stage(GLenum type)
+bool Program::has_stages() const
 {
+       for(unsigned i=0; i<MAX_STAGES; ++i)
+               if(stage_ids[i])
+                       return true;
+       return false;
+}
+
+unsigned Program::add_stage(Stage type)
+{
+       GLenum gl_type;
        switch(type)
        {
-       case GL_VERTEX_SHADER: { static Require _req(ARB_vertex_shader); } break;
-       case GL_GEOMETRY_SHADER: { static Require _req(ARB_geometry_shader4); } break;
-       case GL_FRAGMENT_SHADER: { static Require _req(ARB_fragment_shader); } break;
+       case VERTEX: { static Require _req(ARB_vertex_shader); gl_type = GL_VERTEX_SHADER; } break;
+       case GEOMETRY: { static Require _req(ARB_geometry_shader4); gl_type = GL_GEOMETRY_SHADER; } break;
+       case FRAGMENT: { static Require _req(ARB_fragment_shader); gl_type = GL_FRAGMENT_SHADER; } break;
        default: throw invalid_argument("Program::add_stage");
        }
 
-       unsigned stage_id = glCreateShader(type);
-       stage_ids.push_back(stage_id);
+       if(stage_ids[type])
+               throw invalid_operation("Program::add_stage");
+
+       unsigned stage_id = glCreateShader(gl_type);
+       stage_ids[type] = stage_id;
        glAttachShader(id, stage_id);
 
        return stage_id;
@@ -132,9 +146,9 @@ void Program::add_glsl_stages(const GlslModule &mod, const map<string, int> &spe
                unsigned stage_id = 0;
                switch(*i)
                {
-               case SL::Stage::VERTEX: stage_id = add_stage(GL_VERTEX_SHADER); break;
-               case SL::Stage::GEOMETRY: stage_id = add_stage(GL_GEOMETRY_SHADER); break;
-               case SL::Stage::FRAGMENT: stage_id = add_stage(GL_FRAGMENT_SHADER); break;
+               case SL::Stage::VERTEX: stage_id = add_stage(VERTEX); break;
+               case SL::Stage::GEOMETRY: stage_id = add_stage(GEOMETRY); break;
+               case SL::Stage::FRAGMENT: stage_id = add_stage(FRAGMENT); break;
                default: throw invalid_operation("Program::add_glsl_stages");
                }
 
@@ -194,25 +208,24 @@ void Program::add_spirv_stages(const SpirVModule &mod, const map<string, int> &s
        module = &mod;
 
        const vector<SpirVModule::EntryPoint> &entry_points = mod.get_entry_points();
-       std::set<SpirVModule::Stage> stages;
+       unsigned n_stages = 0;
+       unsigned used_stage_ids[MAX_STAGES];
        for(vector<SpirVModule::EntryPoint>::const_iterator i=entry_points.begin(); i!=entry_points.end(); ++i)
        {
-               if(stages.count(i->stage))
-                       throw invalid_argument("Program::add_spirv_stages");
-
+               unsigned stage_id = 0;
                switch(i->stage)
                {
-               case SpirVModule::VERTEX: add_stage(GL_VERTEX_SHADER); break;
-               case SpirVModule::GEOMETRY: add_stage(GL_GEOMETRY_SHADER); break;
-               case SpirVModule::FRAGMENT: add_stage(GL_FRAGMENT_SHADER); break;
+               case SpirVModule::VERTEX: stage_id = add_stage(VERTEX); break;
+               case SpirVModule::GEOMETRY: stage_id = add_stage(GEOMETRY); break;
+               case SpirVModule::FRAGMENT: stage_id = add_stage(FRAGMENT); break;
                default: throw invalid_operation("Program::add_spirv_stages");
                }
 
-               stages.insert(i->stage);
+               used_stage_ids[n_stages++] = stage_id;
        }
 
        const vector<UInt32> &code = mod.get_code();
-       glShaderBinary(stage_ids.size(), &stage_ids[0], GL_SHADER_BINARY_FORMAT_SPIR_V, &code[0], code.size()*4);
+       glShaderBinary(n_stages, used_stage_ids, GL_SHADER_BINARY_FORMAT_SPIR_V, &code[0], code.size()*4);
 
        if(!spec_values.empty() && !transient)
                transient = new TransientData;
@@ -234,8 +247,9 @@ void Program::add_spirv_stages(const SpirVModule &mod, const map<string, int> &s
        }
 
        vector<SpirVModule::EntryPoint>::const_iterator j=entry_points.begin();
-       for(vector<unsigned>::const_iterator i=stage_ids.begin(); i!=stage_ids.end(); ++i, ++j)
-               glSpecializeShader(*i, j->name.c_str(), spec_id_array.size(), &spec_id_array[0], &spec_value_array[0]);
+       for(unsigned i=0; i<MAX_STAGES; ++i)
+               if(stage_ids[i])
+                       glSpecializeShader(stage_ids[i], j->name.c_str(), spec_id_array.size(), &spec_id_array[0], &spec_value_array[0]);
 }
 
 #pragma GCC diagnostic push
@@ -245,7 +259,17 @@ void Program::attach_shader(Shader &shader)
        unsigned shader_id = shader.steal_id();
        if(!shader_id)
                throw invalid_argument("Program::attach_shader");
-       stage_ids.push_back(shader_id);
+
+       int type;
+       glGetShaderiv(shader_id, GL_SHADER_TYPE, &type);
+       switch(type)
+       {
+       case GL_VERTEX_SHADER: stage_ids[VERTEX] = shader_id; break;
+       case GL_GEOMETRY_SHADER: stage_ids[GEOMETRY] = shader_id; break;
+       case GL_FRAGMENT_SHADER: stage_ids[FRAGMENT] = shader_id; break;
+       }
+
+       glAttachShader(id, shader_id);
        compile_glsl_stage(shader_id);
 }
 
@@ -285,7 +309,7 @@ void Program::bind_fragment_data(unsigned index, const string &name)
 
 void Program::link()
 {
-       if(stage_ids.empty())
+       if(!has_stages())
                throw invalid_operation("Program::link");
 
        uniforms.clear();

diff --git a/source/core/program.h b/source/core/program.h
index 201d927037c57edf0d1464ca1af4002fb28a6d1a..090d8ed5ebc5c4d191ab24d13f7cef402502cdc3 100644 (file)
--- a/source/core/program.h
+++ b/source/core/program.h
@@ -101,6 +101,14 @@ public:
        };
 
 private:
+       enum Stage
+       {
+               VERTEX,
+               GEOMETRY,
+               FRAGMENT,
+               MAX_STAGES
+       };
+
        struct TransientData
        {
                std::map<std::string, unsigned> textures;
@@ -109,7 +117,7 @@ private:
        };
 
        unsigned id;
-       std::vector<unsigned> stage_ids;
+       unsigned stage_ids[MAX_STAGES];
        const Module *module;
        TransientData *transient;
        bool linked;
@@ -138,7 +146,8 @@ public:
 
        void add_stages(const Module &, const std::map<std::string, int> & = std::map<std::string, int>());
 private:
-       unsigned add_stage(GLenum);
+       bool has_stages() const;
+       unsigned add_stage(Stage);
        void add_glsl_stages(const GlslModule &, const std::map<std::string, int> &);
        void compile_glsl_stage(unsigned);
        void add_spirv_stages(const SpirVModule &, const std::map<std::string, int> &);